1. Field of the Invention
The present invention relates to an electronic connector terminal, and more particularly to an electronic connector terminal produced by punching a thin metal plate in a desired shape followed by plating with Au or other high cost metals.
2. Description of the Related Art
An electronic connector terminal is generally formed by punching a thin plate of electrically conductive material into a predetermined shape. Such an electronic connector terminal usually comprises planar parts defined by front and back faces of a punched out piece and peripheral or lateral parts formed by the punching of the thin plate. Generally the electronic connector terminal is categorized into two kinds of terminals; one is a terminal disposed such that the planar part of the thin plate includes a connection to a connector housing when inserted therein, and another is a terminal disposed such that the peripheral or lateral part includes a connection to the connector housing when inserted therein. The terminal, which is configured to have the connection point on the lateral part has advantages in that the terminal is easier to maintain a required contact pressure than the terminal configured to have a connection point on the lateral part and in which the terminal can be disposed in a narrow pitch.
Generally, an electronic connector terminal is applied with plating on predetermined surfaces of the terminal so as to prevent degradation of connecter performance due to oxidation during long usage thereby enhancing electrical conductivity. Conventionally, in the terminal configured to have the electronic connection on the lateral part, the electronic plating is provided on the entire surface of the terminal. Therefore, there is a disadvantage relating to the large amounts of gold (Au) or other high cost metals used for plating the required surfaces, thereby significantly increasing the product cost thereof.
With respect to the above noted disadvantages, the terminal with plating only on the connection point of the lateral part has been proposed. For example, a method comprising the following steps has been proposed in Japanese Patent (Laid-Open) No. Showa 49-114796 and the steps are:
stacking a plurality of connector terminals; and
plating thereon such that unnecessary plating layers can not be deposited on planar parts of a fork-shaped spring.
The planar part may be oxidized during long term usage and the connector performance thereof may be degraded even though the planar part is not subjected to circumstances which cause oxidation as is the lateral part. With respect to this problem, a contact element having a planar part covered with an insulation film has been proposed in Japanese Utility Model (Laid-Open) No. Heisei 5-90834. This contact element is formed by masking the part on which the insulator film is not deposited, and thereafter, dipping the contact in a fluorine-system resin solution to form the insulation film thereon.
However, the above process requires a masking step in which the contact including the plating layer must be masked after the Au plating of the contact portion. This is followed by dipping in the fluorine-system resin solution thereby increasing product costs because additional production processes are required and process steps are increased resulting in an expenditure of time and effort as well as requiring masking materials and the fluorine-system resin solution.
The inventor herein has proposed, in U.S. patent application Ser. No. 10/796,624 filed on Mar. 9, 2004, an electric terminal having Au plating of different thickness in the major plane and the lateral plane.
Even in light of the above described techniques, there is still a significant need for an electronic terminal which is produced easily and inexpensively by reducing the amount of high cost metals necessary for plating without requiring additional production processes.